I calibrated the VCO frequency as a function of the applied input voltage.
The range is approximately +/- 5 MHz, which is large enough to cover the arm's FSR of 3.75MHz.
======== measured parameters ======
center frequency: 79.5 MHz
VCO range: 74MHz - 84MHz
coefficient : 1.22MHz/ V (+/- 2V range)
nominal RF power: -0.66 dBm
(Note: The measurement was done by using Giga-tronics hand-hold power meter.)
Tomorrow I will check the VCO part, especially I am curious about the VCO range.